Automated bone distraction apparatus is known but requires regular periodic adjustment by a skilled professional. As reported by Ilizarov in Clinical Orthopaedics and Related Research, No. 250, January 1990, the rate and frequency of bone distraction may have to be slowed, speeded up, or even reversed, depending upon the quality of bone formation in the distraction gap, the response of the soft tissues and nerves to elongation, and other considerations. If the distraction rate progresses too quickly, one of the first places it will be noticed is in the blood supply to the distal side of the break. If the blood supply is being compromised due to stretching the soft tissue too rapidly, the temperature of the tissue on the distal side of the break decreases. An additional symptom of hyper-distraction is lower oxygen concentration on the distal side of the distraction.
It is an object of the present invention to provide a bone distraction apparatus which incorporates a portable programmable controller and motor drive which may be carried at all times by the patient and which has appropriate built in safeguards to prevent tissue or bone damage due to distraction at improper rates or frequency of distractions,